Tau neutrinos were observed for the first time in 2000 at Fermilab. Today, IceCube scientists have detected high-energy tau neutrinos from deep space, suggesting that neutrino transformations occur not only in lab experiments but also over cosmic distances.

Underneath the vast, frozen landscape of the South Pole lies IceCube, a gigantic observatory dedicated to finding ghostly subatomic particles called neutrinos. Neutrinos stream through Earth from all directions, but they are lightweight, abundant and hardly interact with their surroundings. A forthcoming upgrade to the IceCube detector will provide deeper insights into the elusive particles.

From Big Picture Science, Feb. 18, 2019: Fermilab scientist Anne Schukraft is interviewed in this podcast episode about ghostly particles called neutrinos — intriguing partly because they came decades before we had the means to prove their existence.

From The Washington Post, July 12, 2018: At the IceCube experiment at Earth’s South Pole, 5,160 sensors buried more than a mile beneath the ice detected a single ghostly neutrino as it interacted with an atom. Scientists then traced the particle back to the galaxy that created it.
The cosmic achievement is the first time scientists have detected a high-energy neutrino and been able to pinpoint where it came from.